import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.Closeable; import java.io.FileInputStream; import java.io.FileWriter; import java.io.IOException; import java.io.InputStreamReader; import java.io.PrintWriter; import java.lang.reflect.Array; import java.util.*; public class Main implements Runnable { static ContestScanner in; static Writer out; public static void main(String[] args) { new Thread(null, new Main(), "", 16 * 1024 * 1024).start(); } public void run() { Main main = new Main(); try { in = new ContestScanner(); out = new Writer(); main.solve(); out.close(); in.close(); } catch (IOException e) { e.printStackTrace(); } } void solve() throws IOException { int r = in.nextInt(); int c = in.nextInt(); long t = in.nextLong(); int sy = in.nextInt(); int sx = in.nextInt(); int gy = in.nextInt(); int gx = in.nextInt(); char[][] map = new char[r][c]; for (int i = 0; i < r; i++) { map[i] = in.nextToken().toCharArray(); } double[][] a = new double[r * c][r * c]; double[][] f = new double[1][r * c]; int[] dy = {-1, 0, 1, 0}; int[] dx = {0, 1, 0, -1}; f[0][sy * c + sx] = 1; for (int i = 0; i < r; i++) { for (int j = 0; j < c; j++) { final int id = i * c + j; double ok = 0; for (int k = 0; k < 4; k++) { int ny = i + dy[k]; int nx = j + dx[k]; if(ny < 0 || ny >= r || nx < 0 || nx >= c || map[ny][nx] == '#') continue; ok++; } for (int k = 0; k < 4; k++) { int ny = i + dy[k]; int nx = j + dx[k]; if(ny < 0 || ny >= r || nx < 0 || nx >= c || map[ny][nx] == '#') continue; a[id][ny * c + nx] = 1 / ok; } if(ok == 0) { a[id][id] = 1; } } } double[][] res = modfib(t, f, a); // for (int i = 0; i < r; i++) { // for (int j = 0; j < c; j++) { // System.out.printf("%.4f ", res[0][i * c + j]); // } // System.out.println(); // } System.out.println(res[0][gy * c + gx]); } double[][] modfib(long n, double[][] f, double[][] a){ if(n == 0) return f; // n--; while(n>0){ if((n&1)==1){ f = mult(f, a); } a = mult(a, a); n >>= 1; } return f; } double[][] mult(double[][] a, double[][] b){ double[][] res = new double[a.length][b[0].length]; for(int i=0; i extends HashMap{ @Override public Integer get(Object key){return containsKey(key)?super.get(key):0;} public void add(T key,int v){put(key,get(key)+v);} public void add(T key){put(key,get(key)+1);} public void sub(T key){final int v=get(key);if(v==1)remove(key);else put(key,v-1);} public MultiSet merge(MultiSet set) {MultiSets,l;if(this.size()e:s.entrySet())l.add(e.getKey(),e.getValue());return l;} } class Writer extends PrintWriter{ public Writer(String filename)throws IOException {super(new BufferedWriter(new FileWriter(filename)));} public Writer()throws IOException{super(System.out);} } class ContestScanner implements Closeable{ private BufferedReader in;private int c=-2; public ContestScanner()throws IOException {in=new BufferedReader(new InputStreamReader(System.in));} public ContestScanner(String filename)throws IOException {in=new BufferedReader(new InputStreamReader(new FileInputStream(filename)));} public String nextToken()throws IOException { StringBuilder sb=new StringBuilder(); while((c=in.read())!=-1&&Character.isWhitespace(c)); while(c!=-1&&!Character.isWhitespace(c)){sb.append((char)c);c=in.read();} return sb.toString(); } public String readLine()throws IOException{ StringBuilder sb=new StringBuilder();if(c==-2)c=in.read(); while(c!=-1&&c!='\n'&&c!='\r'){sb.append((char)c);c=in.read();} return sb.toString(); } public long nextLong()throws IOException,NumberFormatException {return Long.parseLong(nextToken());} public int nextInt()throws NumberFormatException,IOException {return(int)nextLong();} public double nextDouble()throws NumberFormatException,IOException {return Double.parseDouble(nextToken());} public void close() throws IOException {in.close();} }